Mojo: More plumbing to support sending handles over MessagePipes.

mojo/system/message_pipe_dispatcher.cc

Index: mojo/system/message_pipe_dispatcher.cc
diff --git a/mojo/system/message_pipe_dispatcher.cc b/mojo/system/message_pipe_dispatcher.cc
index df4def127dcb777724af4a2fd0b983b7e71f6921..e0270f8b30177e32e7b86b7a2ce491715bc3ca7e 100644
--- a/mojo/system/message_pipe_dispatcher.cc
+++ b/mojo/system/message_pipe_dispatcher.cc
@@ -45,6 +45,9 @@ MojoResult MessagePipeDispatcher::WriteMessageImplNoLock(
     const void* bytes, uint32_t num_bytes,
     const std::vector<Dispatcher*>* dispatchers,
     MojoWriteMessageFlags flags) {
+  DCHECK(!dispatchers || (dispatchers->size() > 0 &&
+                          dispatchers->size() <= kMaxMessageNumHandles));
+
   lock().AssertAcquired();
 
   if (!VerifyUserPointer<void>(bytes, num_bytes))
@@ -52,15 +55,6 @@ MojoResult MessagePipeDispatcher::WriteMessageImplNoLock(
   if (num_bytes > kMaxMessageNumBytes)
     return MOJO_RESULT_RESOURCE_EXHAUSTED;
 
-  if (dispatchers) {
-    DCHECK_GT(dispatchers->size(), 0u);
-    DCHECK_LE(dispatchers->size(), kMaxMessageNumHandles);
-
-    // TODO(vtl)
-    NOTIMPLEMENTED();
-    return MOJO_RESULT_UNIMPLEMENTED;
-  }
-
   return message_pipe_->WriteMessage(port_,
                                      bytes, num_bytes,
                                      dispatchers,